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Müller L, Power Guerra N, Stenzel J, Rühlmann C, Lindner T, Krause BJ, Vollmar B, Teipel S, Kuhla A. Long-Term Caloric Restriction Attenuates β-Amyloid Neuropathology and Is Accompanied by Autophagy in APPswe/PS1delta9 Mice. Nutrients 2021; 13:nu13030985. [PMID: 33803798 PMCID: PMC8003277 DOI: 10.3390/nu13030985] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/09/2021] [Accepted: 03/16/2021] [Indexed: 12/14/2022] Open
Abstract
Caloric restriction (CR) slows the aging process, extends lifespan, and exerts neuroprotective effects. It is widely accepted that CR attenuates β-amyloid (Aβ) neuropathology in models of Alzheimer's disease (AD) by so-far unknown mechanisms. One promising process induced by CR is autophagy, which is known to degrade aggregated proteins such as amyloids. In addition, autophagy positively regulates glucose uptake and may improve cerebral hypometabolism-a hallmark of AD-and, consequently, neural activity. To evaluate this hypothesis, APPswe/PS1delta9 (tg) mice and their littermates (wild-type, wt) underwent CR for either 16 or 68 weeks. Whereas short-term CR for 16 weeks revealed no noteworthy changes of AD phenotype in tg mice, long-term CR for 68 weeks showed beneficial effects. Thus, cerebral glucose metabolism and neuronal integrity were markedly increased upon 68 weeks CR in tg mice, indicated by an elevated hippocampal fluorodeoxyglucose [18F] ([18F]FDG) uptake and increased N-acetylaspartate-to-creatine ratio using positron emission tomography/computer tomography (PET/CT) imaging and magnet resonance spectroscopy (MRS). Improved neuronal activity and integrity resulted in a better cognitive performance within the Morris Water Maze. Moreover, CR for 68 weeks caused a significant increase of LC3BII and p62 protein expression, showing enhanced autophagy. Additionally, a significant decrease of Aβ plaques in tg mice in the hippocampus was observed, accompanied by reduced microgliosis as indicated by significantly decreased numbers of iba1-positive cells. In summary, long-term CR revealed an overall neuroprotective effect in tg mice. Further, this study shows, for the first time, that CR-induced autophagy in tg mice accompanies the observed attenuation of Aβ pathology.
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Affiliation(s)
- Luisa Müller
- Rudolf-Zenker-Institute for Experimental Surgery, Medical University Rostock, 18057 Rostock, Germany; (L.M.); (N.P.G.); (C.R.); (B.V.)
- Department of Psychosomatic Medicine and Psychotherapy, University of Rostock, 18147 Rostock, Germany;
- Centre for Transdisciplinary Neurosciences Rostock (CTNR), University of Rostock, 18147 Rostock, Germany
| | - Nicole Power Guerra
- Rudolf-Zenker-Institute for Experimental Surgery, Medical University Rostock, 18057 Rostock, Germany; (L.M.); (N.P.G.); (C.R.); (B.V.)
| | - Jan Stenzel
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, 18057 Rostock, Germany; (J.S.); (T.L.); (B.J.K.)
| | - Claire Rühlmann
- Rudolf-Zenker-Institute for Experimental Surgery, Medical University Rostock, 18057 Rostock, Germany; (L.M.); (N.P.G.); (C.R.); (B.V.)
| | - Tobias Lindner
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, 18057 Rostock, Germany; (J.S.); (T.L.); (B.J.K.)
| | - Bernd J. Krause
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, 18057 Rostock, Germany; (J.S.); (T.L.); (B.J.K.)
- Department of Nuclear Medicine, Rostock University Medical Center, 18057 Rostock, Germany
| | - Brigitte Vollmar
- Rudolf-Zenker-Institute for Experimental Surgery, Medical University Rostock, 18057 Rostock, Germany; (L.M.); (N.P.G.); (C.R.); (B.V.)
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, 18057 Rostock, Germany; (J.S.); (T.L.); (B.J.K.)
| | - Stefan Teipel
- Department of Psychosomatic Medicine and Psychotherapy, University of Rostock, 18147 Rostock, Germany;
- Centre for Transdisciplinary Neurosciences Rostock (CTNR), University of Rostock, 18147 Rostock, Germany
- German Center for Neurodegenerative Diseases (DZNE)–Rostock/Greifswald, 18147 Rostock and 17489 Greifswald, Germany
| | - Angela Kuhla
- Rudolf-Zenker-Institute for Experimental Surgery, Medical University Rostock, 18057 Rostock, Germany; (L.M.); (N.P.G.); (C.R.); (B.V.)
- Centre for Transdisciplinary Neurosciences Rostock (CTNR), University of Rostock, 18147 Rostock, Germany
- Correspondence: ; Tel.: +49-381-494-2503
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Focke C, Blume T, Zott B, Shi Y, Deussing M, Peters F, Schmidt C, Kleinberger G, Lindner S, Gildehaus FJ, Beyer L, von Ungern-Sternberg B, Bartenstein P, Ozmen L, Baumann K, Dorostkar MM, Haass C, Adelsberger H, Herms J, Rominger A, Brendel M. Early and Longitudinal Microglial Activation but Not Amyloid Accumulation Predicts Cognitive Outcome in PS2APP Mice. J Nucl Med 2018; 60:548-554. [DOI: 10.2967/jnumed.118.217703] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 09/10/2018] [Indexed: 02/06/2023] Open
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Tolomeo D, Micotti E, Serra SC, Chappell M, Snellman A, Forloni G. Chemical exchange saturation transfer MRI shows low cerebral 2-deoxy-D-glucose uptake in a model of Alzheimer's Disease. Sci Rep 2018; 8:9576. [PMID: 29934551 PMCID: PMC6015016 DOI: 10.1038/s41598-018-27839-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 06/11/2018] [Indexed: 12/17/2022] Open
Abstract
Glucose is the central nervous system's only energy source. Imaging techniques capable to detect pathological alterations of the brain metabolism are useful in different diagnostic processes. Such techniques are also beneficial for assessing the evaluation efficacy of therapies in pre-clinical and clinical stages of diseases. Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) is a possible alternative to positron emission tomography (PET) imaging that has been widely explored in cancer research in humans and animal models. We propose that pathological alterations in brain 2-deoxy-D-glucose (2DG) uptake, typical of neurodegenerative diseases, can be detected with CEST MRI. Transgenic mice overexpressing a mutated form of amyloid precusrsor protein (APP23), a model of Alzheimer's disease, analyzed with CEST MRI showed a clear reduction of 2DG uptake in different brain regions. This was reminiscent of the cerebral condition observed in Alzheimer's patients. The results indicate the feasibility of CEST for analyzing the brain metabolic state, with better image resolution than PET in experimental models.
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Affiliation(s)
- Daniele Tolomeo
- Laboratory of Biology of Neurodegenerative Disorders, Department of Neuroscience, IRCCS, Mario Negri Institute for Pharmacological Research, Milan, (MI), Italy
| | - Edoardo Micotti
- Laboratory of Biology of Neurodegenerative Disorders, Department of Neuroscience, IRCCS, Mario Negri Institute for Pharmacological Research, Milan, (MI), Italy
| | | | - Michael Chappell
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, 6396, Oxford, UK
| | - Anniina Snellman
- Medicity Research Laboratory, University of Turku, (Tykistökatu 6, FI-20510), Turku, Finland.,Turku PET Centre, University of Turku, (Kiinamyllynkatu 4-8, FI-20520,), Turku, Finland
| | - Gianluigi Forloni
- Laboratory of Biology of Neurodegenerative Disorders, Department of Neuroscience, IRCCS, Mario Negri Institute for Pharmacological Research, Milan, (MI), Italy.
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Mouse models of neurodegenerative disease: preclinical imaging and neurovascular component. Brain Imaging Behav 2017; 12:1160-1196. [PMID: 29075922 DOI: 10.1007/s11682-017-9770-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurodegenerative diseases represent great challenges for basic science and clinical medicine because of their prevalence, pathologies, lack of mechanism-based treatments, and impacts on individuals. Translational research might contribute to the study of neurodegenerative diseases. The mouse has become a key model for studying disease mechanisms that might recapitulate in part some aspects of the corresponding human diseases. Neurodegenerative disorders are very complicated and multifactorial. This has to be taken in account when testing drugs. Most of the drugs screening in mice are very difficult to be interpretated and often useless. Mouse models could be condiderated a 'pathway models', rather than as models for the whole complicated construct that makes a human disease. Non-invasive in vivo imaging in mice has gained increasing interest in preclinical research in the last years thanks to the availability of high-resolution single-photon emission computed tomography (SPECT), positron emission tomography (PET), high field Magnetic resonance, Optical Imaging scanners and of highly specific contrast agents. Behavioral test are useful tool to characterize different animal models of neurodegenerative pathology. Furthermore, many authors have observed vascular pathological features associated to the different neurodegenerative disorders. Aim of this review is to focus on the different existing animal models of neurodegenerative disorders, describe behavioral tests and preclinical imaging techniques used for diagnose and describe the vascular pathological features associated to these diseases.
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Kuhla A, Rühlmann C, Lindner T, Polei S, Hadlich S, Krause BJ, Vollmar B, Teipel SJ. APPswe/PS1dE9 mice with cortical amyloid pathology show a reduced NAA/Cr ratio without apparent brain atrophy: A MRS and MRI study. NEUROIMAGE-CLINICAL 2017; 15:581-586. [PMID: 28652970 PMCID: PMC5476467 DOI: 10.1016/j.nicl.2017.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/07/2017] [Accepted: 06/08/2017] [Indexed: 12/26/2022]
Abstract
Transgenic animal models of Aβ pathology provide mechanistic insight into some aspects of Alzheimer disease (AD) pathology related to Aβ accumulation. Quantitative neuroimaging is a possible aid to improve translation of mechanistic findings in transgenic models to human end phenotypes of brain morphology or function. Therefore, we combined MRI-based morphometry, MRS-based NAA-assessment and quantitative histology of neurons and amyloid plaque load in the APPswe/PS1dE9 mouse model to determine the interrelationship between morphological changes, changes in neuron numbers and amyloid plaque load with reductions of NAA levels as marker of neuronal functional viability. The APPswe/PS1dE9 mouse showed an increase of Aβ plaques, loss of neurons and an impairment of NAA/Cr ratio, which however was not accompanied with brain atrophy. As brain atrophy is one main characteristic in human AD, conclusions from murine to human AD pathology should be drawn with caution.
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Affiliation(s)
- Angela Kuhla
- Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany.
| | - Claire Rühlmann
- Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
| | - Tobias Lindner
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, Rostock, Germany
| | - Stefan Polei
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, Rostock, Germany
| | - Stefan Hadlich
- Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany
| | - Bernd J Krause
- Department of Nuclear Medicine, Rostock University Medical Center, Rostock, Germany
| | - Brigitte Vollmar
- Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
| | - Stefan J Teipel
- German Center for Neurodegenerative Diseases (DZNE) - Rostock/Greifswald, Rostock, Germany, Department of Psychosomatic Medicine, University of Rostock, Rostock, Germany
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Brendel M, Kleinberger G, Probst F, Jaworska A, Overhoff F, Blume T, Albert NL, Carlsen J, Lindner S, Gildehaus FJ, Ozmen L, Suárez-Calvet M, Bartenstein P, Baumann K, Ewers M, Herms J, Haass C, Rominger A. Increase of TREM2 during Aging of an Alzheimer's Disease Mouse Model Is Paralleled by Microglial Activation and Amyloidosis. Front Aging Neurosci 2017; 9:8. [PMID: 28197095 PMCID: PMC5282474 DOI: 10.3389/fnagi.2017.00008] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/12/2017] [Indexed: 12/23/2022] Open
Abstract
Heterozygous missense mutations in the triggering receptor expressed on myeloid cells 2 (TREM2) have been reported to significantly increase the risk of developing Alzheimer’s disease (AD). Since TREM2 is specifically expressed by microglia in the brain, we hypothesized that soluble TREM2 (sTREM2) levels may increase together with in vivo biomarkers of microglial activity and amyloidosis in an AD mouse model as assessed by small animal positron-emission-tomography (μPET). In this cross-sectional study, we examined a strong amyloid mouse model (PS2APP) of four age groups by μPET with [18F]-GE180 (glial activation) and [18F]-florbetaben (amyloidosis), followed by measurement of sTREM2 levels and amyloid levels in the brain. Pathology affected brain regions were compared between tracers (dice similarity coefficients) and pseudo-longitudinally. μPET results of both tracers were correlated with terminal TREM2 levels. The brain sTREM2 levels strongly increased with age of PS2APP mice (5 vs. 16 months: +211%, p < 0.001), and correlated highly with μPET signals of microglial activity (R = 0.89, p < 0.001) and amyloidosis (R = 0.92, p < 0.001). Dual μPET enabled regional mapping of glial activation and amyloidosis in the mouse brain, which progressed concertedly leading to a high overlap in aged PS2APP mice (dice similarity 67%). Together, these results substantiate the use of in vivo μPET measurements in conjunction with post mortem sTREM2 in future anti-inflammatory treatment trials. Taking human data into account sTREM2 may increase during active amyloid deposition.
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Affiliation(s)
- Matthias Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München Munich, Germany
| | - Gernot Kleinberger
- Department of Biochemistry, Biomedical Center (BMC), Ludwig-Maximilians-Universität MünchenMunich, Germany; Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-Universität MünchenMunich, Germany
| | - Federico Probst
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München Munich, Germany
| | - Anna Jaworska
- DZNE-German Center for Neurodegenerative DiseasesMunich, Germany; Laboratory of Neurodegeneration, International Institute of Molecular and Cell BiologyWarsaw, Poland
| | - Felix Overhoff
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München Munich, Germany
| | - Tanja Blume
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München Munich, Germany
| | - Nathalie L Albert
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München Munich, Germany
| | - Janette Carlsen
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München Munich, Germany
| | - Franz Josef Gildehaus
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München Munich, Germany
| | - Laurence Ozmen
- Roche Pharma Research and Early Development, Neuroscience Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd. Basel, Switzerland
| | - Marc Suárez-Calvet
- Department of Biochemistry, Biomedical Center (BMC), Ludwig-Maximilians-Universität MünchenMunich, Germany; DZNE-German Center for Neurodegenerative DiseasesMunich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität MünchenMunich, Germany; Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-Universität MünchenMunich, Germany
| | - Karlheinz Baumann
- Roche Pharma Research and Early Development, Neuroscience Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd. Basel, Switzerland
| | - Michael Ewers
- DZNE-German Center for Neurodegenerative Diseases Munich, Germany
| | - Jochen Herms
- Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-Universität MünchenMunich, Germany; DZNE-German Center for Neurodegenerative DiseasesMunich, Germany
| | - Christian Haass
- Department of Biochemistry, Biomedical Center (BMC), Ludwig-Maximilians-Universität MünchenMunich, Germany; Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-Universität MünchenMunich, Germany; DZNE-German Center for Neurodegenerative DiseasesMunich, Germany
| | - Axel Rominger
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität MünchenMunich, Germany; Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-Universität MünchenMunich, Germany
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Fluselenamyl: A Novel Benzoselenazole Derivative for PET Detection of Amyloid Plaques (Aβ) in Alzheimer's Disease. Sci Rep 2016; 6:35636. [PMID: 27805057 PMCID: PMC5090206 DOI: 10.1038/srep35636] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 09/30/2016] [Indexed: 02/02/2023] Open
Abstract
Fluselenamyl (5), a novel planar benzoselenazole shows traits desirable of enabling noninvasive imaging of Aβ pathophysiology in vivo; labeling of both diffuse (an earlier manifestation of neuritic plaques) and fibrillar plaques in Alzheimer's disease (AD) brain sections, and remarkable specificity for mapping Aβ compared with biomarker proteins of other neurodegenerative diseases. Employing AD homogenates, [18F]-9, a PET tracer demonstrates superior (2-10 fold higher) binding affinity than approved FDA tracers, while also indicating binding to high affinity site on Aβ plaques. Pharmacokinetic studies indicate high initial influx of [18F]-9 in normal mice brains accompanied by rapid clearance in the absence of targeted plaques. Following incubation in human serum, [18F]-9 indicates presence of parental compound up to 3h thus indicating its stability. Furthermore, in vitro autoradiography studies of [18F]-9 with AD brain tissue sections and ex vivo autoradiography studies in transgenic mouse brain sections show cortical Aβ binding, and a fair correlation with Aβ immunostaining. Finally, multiphoton- and microPET/CT imaging indicate its ability to penetrate brain and label parenchymal plaques in transgenic mice. Following further validation of its performance in other AD rodent models and nonhuman primates, Fluselenamyl could offer a platform technology for monitoring earliest stages of Aβ pathophysiology in vivo.
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Abbaszadeh S, Gu Y, Reynolds PD, Levin CS. Characterization of a sub-assembly of 3D position sensitive cadmium zinc telluride detectors and electronics from a sub-millimeter resolution PET system. Phys Med Biol 2016; 61:6733-6753. [PMID: 27551981 DOI: 10.1088/0031-9155/61/18/6733] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cadmium zinc telluride (CZT) offers key advantages for small animal positron emission tomography (PET), including high spatial and energy resolution and simple metal deposition for fabrication of very small pixel arrays. Previous studies have investigated the intrinsic spatial, energy, and timing resolution of an individual sub-millimeter resolution CZT detector. In this work we present the first characterization results of a system of these detectors. The 3D position sensitive dual-CZT detector module and readout electronics developed in our lab was scaled up to complete a significant portion of the final PET system. This sub-system was configured as two opposing detection panels containing a total of twelve [Formula: see text] mm monolithic CZT crystals for proof of concept. System-level characterization studies, including optimizing the trigger threshold of each channel's comparators, were performed. 68Ge and 137Cs radioactive isotopes were used to characterize the energy resolution of all 468 anode channels in the sub-system. The mean measured global 511 keV photopeak energy resolution over all anodes was found to be [Formula: see text]% FWHM after correction for photon interaction depth-dependent signal variation. The measured global time resolution was 37 ns FWHM, a parameter to be further optimized, and the intrinsic spatial resolution was 0.76 mm FWHM.
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Affiliation(s)
- Shiva Abbaszadeh
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
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Möhle L, Israel N, Paarmann K, Krohn M, Pietkiewicz S, Müller A, Lavrik IN, Buguliskis JS, Schott BH, Schlüter D, Gundelfinger ED, Montag D, Seifert U, Pahnke J, Dunay IR. Chronic Toxoplasma gondii infection enhances β-amyloid phagocytosis and clearance by recruited monocytes. Acta Neuropathol Commun 2016; 4:25. [PMID: 26984535 PMCID: PMC4793516 DOI: 10.1186/s40478-016-0293-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 02/19/2016] [Indexed: 01/02/2023] Open
Abstract
INTRODUCTION Alzheimer's disease (AD) is associated with the accumulation of β-amyloid (Aβ) as senile plaques in the brain, thus leading to neurodegeneration and cognitive impairment. Plaque formation depends not merely on the amount of generated Aβ peptides, but more importantly on their effective removal. Chronic infections with neurotropic pathogens, most prominently the parasite Toxoplasma (T.) gondii, are frequent in the elderly, and it has been suggested that the resulting neuroinflammation may influence the course of AD. In the present study, we investigated how chronic T. gondii infection and resulting neuroinflammation affect plaque deposition and removal in a mouse model of AD. RESULTS Chronic infection with T. gondii was associated with reduced Aβ and plaque load in 5xFAD mice. Upon infection, myeloid-derived CCR2(hi) Ly6C(hi) monocytes, CCR2(+) Ly6C(int), and CCR2(+) Ly6C(low) mononuclear cells were recruited to the brain of mice. Compared to microglia, these recruited mononuclear cells showed highly increased phagocytic capacity of Aβ ex vivo. The F4/80(+) Ly6C(low) macrophages expressed high levels of Triggering Receptor Expressed on Myeloid cells 2 (TREM2), CD36, and Scavenger Receptor A1 (SCARA1), indicating phagocytic activity. Importantly, selective ablation of CCR2(+) Ly6C(hi) monocytes resulted in an increased amount of Aβ in infected mice. Elevated insulin-degrading enzyme (IDE), matrix metalloproteinase 9 (MMP9), as well as immunoproteasome subunits β1i/LMP2, β2i/MECL-1, and β5i/LMP7 mRNA levels in the infected brains indicated increased proteolytic Aβ degradation. Particularly, LMP7 was highly expressed by the recruited mononuclear cells in the brain, suggesting a novel mechanism of Aβ clearance. CONCLUSIONS Our results indicate that chronic Toxoplasma infection ameliorates β-amyloidosis in a murine model of AD by activation of the immune system, specifically by recruitment of Ly6C(hi) monocytes and by enhancement of phagocytosis and degradation of soluble Aβ. Our findings provide evidence for a modulatory role of inflammation-induced Aβ phagocytosis and degradation by newly recruited peripheral immune cells in the pathophysiology of AD.
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Affiliation(s)
- Luisa Möhle
- Institute for Medical Microbiology and Hospital Hygiene, University of Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Nicole Israel
- Institute for Molecular and Clinical Immunology, University of Magdeburg, Magdeburg, Germany
| | - Kristin Paarmann
- Department of Pathology (PAT), Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
- Neurogenetics, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Markus Krohn
- Department of Pathology (PAT), Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - Sabine Pietkiewicz
- Department of Translational Inflammation Research, Institute of Experimental Internal Medicine, University of Magdeburg, Magdeburg, Germany
| | - Andreas Müller
- Institute for Molecular and Clinical Immunology, University of Magdeburg, Magdeburg, Germany
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Inna N Lavrik
- Department of Translational Inflammation Research, Institute of Experimental Internal Medicine, University of Magdeburg, Magdeburg, Germany
| | | | - Björn H Schott
- Center for Behavioral Brain Sciences (CBBS), University of Magdeburg, Magdeburg, Germany
- Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Department of Psychiatry and Psychotherapy, Campus Mitte, Charité Universitätsmedizin, Berlin, Germany
| | - Dirk Schlüter
- Institute for Medical Microbiology and Hospital Hygiene, University of Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), University of Magdeburg, Magdeburg, Germany
| | - Eckart D Gundelfinger
- Center for Behavioral Brain Sciences (CBBS), University of Magdeburg, Magdeburg, Germany
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Medical Faculty, University of Magdeburg, Magdeburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Dirk Montag
- Neurogenetics, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ulrike Seifert
- Institute for Molecular and Clinical Immunology, University of Magdeburg, Magdeburg, Germany
| | - Jens Pahnke
- Department of Pathology (PAT), Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
- University of Lübeck (UzL), LIED, Lübeck, Germany
- Leibniz Institute of Plant Biochemistry (IPB), Halle, Germany
| | - Ildiko Rita Dunay
- Institute for Medical Microbiology and Hospital Hygiene, University of Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany.
- Center for Behavioral Brain Sciences (CBBS), University of Magdeburg, Magdeburg, Germany.
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Overhoff F, Brendel M, Jaworska A, Korzhova V, Delker A, Probst F, Focke C, Gildehaus FJ, Carlsen J, Baumann K, Haass C, Bartenstein P, Herms J, Rominger A. Automated Spatial Brain Normalization and Hindbrain White Matter Reference Tissue Give Improved [(18)F]-Florbetaben PET Quantitation in Alzheimer's Model Mice. Front Neurosci 2016; 10:45. [PMID: 26973442 PMCID: PMC4770021 DOI: 10.3389/fnins.2016.00045] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/01/2016] [Indexed: 11/13/2022] Open
Abstract
Preclinical PET studies of β-amyloid (Aβ) accumulation are of growing importance, but comparisons between research sites require standardized and optimized methods for quantitation. Therefore, we aimed to evaluate systematically the (1) impact of an automated algorithm for spatial brain normalization, and (2) intensity scaling methods of different reference regions for Aβ-PET in a large dataset of transgenic mice. PS2APP mice in a 6 week longitudinal setting (N = 37) and another set of PS2APP mice at a histologically assessed narrow range of Aβ burden (N = 40) were investigated by [18F]-florbetaben PET. Manual spatial normalization by three readers at different training levels was performed prior to application of an automated brain spatial normalization and inter-reader agreement was assessed by Fleiss Kappa (κ). For this method the impact of templates at different pathology stages was investigated. Four different reference regions on brain uptake normalization were used to calculate frontal cortical standardized uptake value ratios (SUVRCTX∕REF), relative to raw SUVCTX. Results were compared on the basis of longitudinal stability (Cohen's d), and in reference to gold standard histopathological quantitation (Pearson's R). Application of an automated brain spatial normalization resulted in nearly perfect agreement (all κ≥0.99) between different readers, with constant or improved correlation with histology. Templates based on inappropriate pathology stage resulted in up to 2.9% systematic bias for SUVRCTX∕REF. All SUVRCTX∕REF methods performed better than SUVCTX both with regard to longitudinal stability (d≥1.21 vs. d = 0.23) and histological gold standard agreement (R≥0.66 vs. R≥0.31). Voxel-wise analysis suggested a physiologically implausible longitudinal decrease by global mean scaling. The hindbrain white matter reference (Rmean = 0.75) was slightly superior to the brainstem (Rmean = 0.74) and the cerebellum (Rmean = 0.73). Automated brain normalization with reference region templates presents an excellent method to avoid the inter-reader variability in preclinical Aβ-PET scans. Intracerebral reference regions lacking Aβ pathology serve for precise longitudinal in vivo quantification of [18F]-florbetaben PET. Hindbrain white matter reference performed best when considering the composite of quality criteria.
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Affiliation(s)
- Felix Overhoff
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich Munich, Germany
| | - Anna Jaworska
- DZNE-German Center for Neurodegenerative DiseasesMunich, Germany; Laboratory of Neurodegeneration, International Institute of Molecular and Cell BiologyWarsaw, Poland
| | | | - Andreas Delker
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich Munich, Germany
| | - Federico Probst
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich Munich, Germany
| | - Carola Focke
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich Munich, Germany
| | - Franz-Josef Gildehaus
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich Munich, Germany
| | - Janette Carlsen
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich Munich, Germany
| | - Karlheinz Baumann
- Roche Pharma Research and Early Development, Neuroscience Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd Basel, Switzerland
| | - Christian Haass
- DZNE-German Center for Neurodegenerative DiseasesMunich, Germany; Munich Cluster for Systems Neurology (SyNergy)Munich, Germany; Biomedical Center, Ludwig-Maximilians-University of MunichMunich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, Ludwig-Maximilians-University of MunichMunich, Germany; Munich Cluster for Systems Neurology (SyNergy)Munich, Germany
| | - Jochen Herms
- DZNE-German Center for Neurodegenerative DiseasesMunich, Germany; Munich Cluster for Systems Neurology (SyNergy)Munich, Germany
| | - Axel Rominger
- Department of Nuclear Medicine, Ludwig-Maximilians-University of MunichMunich, Germany; Munich Cluster for Systems Neurology (SyNergy)Munich, Germany
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11
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Brendel M, Probst F, Jaworska A, Overhoff F, Korzhova V, Albert NL, Beck R, Lindner S, Gildehaus FJ, Baumann K, Bartenstein P, Kleinberger G, Haass C, Herms J, Rominger A. Glial Activation and Glucose Metabolism in a Transgenic Amyloid Mouse Model: A Triple-Tracer PET Study. J Nucl Med 2016; 57:954-60. [PMID: 26912428 DOI: 10.2967/jnumed.115.167858] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/02/2016] [Indexed: 12/26/2022] Open
Abstract
UNLABELLED Amyloid imaging by small-animal PET in models of Alzheimer disease (AD) offers the possibility to track amyloidogenesis and brain energy metabolism. Because microglial activation is thought to contribute to AD pathology, we undertook a triple-tracer small-animal PET study to assess microglial activation and glucose metabolism in association with amyloid plaque load in a transgenic AD mouse model. METHODS Groups of PS2APP and C57BL/6 wild-type mice of various ages were examined by small-animal PET. We acquired 90-min dynamic emission data with (18)F-GE180 for imaging activated microglia (18-kD translocator protein ligand [TSPO]) and static 30- to 60-min recordings with (18)F-FDG for energy metabolism and (18)F-florbetaben for amyloidosis. Optimal fusion of PET data was obtained through automatic nonlinear spatial normalization, and SUVRs were calculated. For the novel TSPO tracer (18)F-GE180, we then calculated distribution volume ratios after establishing a suitable reference region. Immunohistochemical analyses with TSPO antisera, methoxy-X04 staining for fibrillary β-amyloid, and ex vivo autoradiography served as terminal gold standard assessments. RESULTS SUVR at 60-90 min after injection gave robust quantitation of (18)F-GE180, which correlated well with distribution volume ratios calculated from the entire recording and using a white matter reference region. Relative to age-matched wild-type, (18)F-GE180 SUVR was slightly elevated in PS2APP mice at 5 mo (+9%; P < 0.01) and distinctly increased at 16 mo (+25%; P < 0.001). Over this age range, there was a high positive correlation between small-animal PET findings of microglial activation with amyloid load (R = 0.85; P < 0.001) and likewise with metabolism (R = 0.61; P < 0.005). Immunohistochemical and autoradiographic findings confirmed the in vivo small-animal PET data. CONCLUSION In this first triple-tracer small-animal PET in a well-established AD mouse model, we found evidence for age-dependent microglial activation. This activation, correlating positively with the amyloid load, implies a relationship between amyloidosis and inflammation in the PS2APP AD mouse model.
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Affiliation(s)
- Matthias Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Federico Probst
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Anna Jaworska
- DZNE-German Center for Neurodegenerative Diseases, Munich, Germany
| | - Felix Overhoff
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | | | - Nathalie L Albert
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Roswitha Beck
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Franz-Josef Gildehaus
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Karlheinz Baumann
- Roche Pharma Research and Early Development, Neuroscience Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Peter Bartenstein
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany SyNergy, Ludwig-Maximilians-University of Munich, Munich, Germany; and
| | - Gernot Kleinberger
- DZNE-German Center for Neurodegenerative Diseases, Munich, Germany SyNergy, Ludwig-Maximilians-University of Munich, Munich, Germany; and Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Christian Haass
- DZNE-German Center for Neurodegenerative Diseases, Munich, Germany SyNergy, Ludwig-Maximilians-University of Munich, Munich, Germany; and Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Jochen Herms
- DZNE-German Center for Neurodegenerative Diseases, Munich, Germany SyNergy, Ludwig-Maximilians-University of Munich, Munich, Germany; and
| | - Axel Rominger
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany SyNergy, Ludwig-Maximilians-University of Munich, Munich, Germany; and
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12
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Brendel M, Jaworska A, Probst F, Overhoff F, Korzhova V, Lindner S, Carlsen J, Bartenstein P, Harada R, Kudo Y, Haass C, Van Leuven F, Okamura N, Herms J, Rominger A. Small-Animal PET Imaging of Tau Pathology with 18F-THK5117 in 2 Transgenic Mouse Models. J Nucl Med 2016; 57:792-8. [PMID: 26912432 DOI: 10.2967/jnumed.115.163493] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 01/21/2016] [Indexed: 11/16/2022] Open
Abstract
Abnormal accumulation of tau aggregates in the brain is one of the hallmarks of Alzheimer disease neuropathology. We visualized tau deposition in vivo with the previously developed 2-arylquinoline derivative (18)F-THK5117 using small-animal PET in conjunction with autoradiography and immunohistochemistry gold standard assessment in 2 transgenic mouse models expressing hyperphosphorylated tau. Small-animal PET recordings were obtained in groups of P301S (n = 11) and biGT mice (n = 16) of different ages, with age-matched wild-type (WT) serving as controls. After intravenous administration of 16 ± 2 MBq of (18)F-THK5117, a dynamic 90-min emission recording was initiated for P301S mice and during 20-50 min after injection for biGT mice, followed by a 15-min transmission scan. After coregistration to the MRI atlas and scaling to the cerebellum, we performed volume-of-interest-based analysis (SUV ratio [SUVR]) and statistical parametric mapping. Small-animal PET results were compared with autoradiography ex vivo and in vitro and further validated with AT8 staining for neurofibrillary tangles. SUVRs calculated from static recordings during the interval of 20-50 min after tracer injection correlated highly with estimates of binding potential based on the entire dynamic emission recordings (R = 0.85). SUVR increases were detected in the brain stem of aged P301S mice (+11%; P < 0.001) and in entorhinal/amygdaloidal areas (+15%; P < 0.001) of biGT mice when compared with WT, whereas aged WT mice did not show increased tracer uptake. Immunohistochemical tau loads correlated with small-animal PET SUVR for both P301S (R = 0.8; P < 0.001) and biGT (R = 0.7; P < 0.001) mice, and distribution patterns of AT8-positive neurons matched voxelwise statistical parametric mapping analysis. Saturable binding of the tracer was verified by autoradiographic blocking studies. In the first dedicated small-animal PET study in 2 different transgenic tauopathy mouse models using the tau tracer (18)F-THK5117, the temporal and spatial progression could be visualized in good correlation with gold standard assessments of tau accumulation. The serial small-animal PET method could afford the means for preclinical testing of novel therapeutic approaches by accommodating interanimal variability at baseline, while detection thresholds in young animals have to be considered.
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Affiliation(s)
- Matthias Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Anna Jaworska
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Federico Probst
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Felix Overhoff
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Viktoria Korzhova
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Janette Carlsen
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | | | | | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany; and
| | | | | | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Axel Rominger
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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13
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Brendel M, Jaworska A, Herms J, Trambauer J, Rötzer C, Gildehaus FJ, Carlsen J, Cumming P, Bylund J, Luebbers T, Bartenstein P, Steiner H, Haass C, Baumann K, Rominger A. Amyloid-PET predicts inhibition of de novo plaque formation upon chronic γ-secretase modulator treatment. Mol Psychiatry 2015; 20:1179-87. [PMID: 26055427 PMCID: PMC4759098 DOI: 10.1038/mp.2015.74] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/31/2015] [Accepted: 04/13/2015] [Indexed: 01/18/2023]
Abstract
In a positron-emission tomography (PET) study with the β-amyloid (Aβ) tracer [(18)F]-florbetaben, we previously showed that Aβ deposition in transgenic mice expressing Swedish mutant APP (APP-Swe) mice can be tracked in vivo. γ-Secretase modulators (GSMs) are promising therapeutic agents by reducing generation of the aggregation prone Aβ42 species without blocking general γ-secretase activity. We now aimed to investigate the effects of a novel GSM [8-(4-Fluoro-phenyl)-[1,2,4]triazolo[1,5-a]pyridin-2-yl]-[1-(3-methyl-[1,2,4]thiadiazol-5-yl)-piperidin-4-yl]-amine (RO5506284) displaying high potency in vitro and in vivo on amyloid plaque burden and used longitudinal Aβ-microPET to trace individual animals. Female transgenic (TG) APP-Swe mice aged 12 months (m) were assigned to vehicle (TG-VEH, n=12) and treatment groups (TG-GSM, n=12), which received daily RO5506284 (30 mg kg(-1)) treatment for 6 months. A total of 131 Aβ-PET recordings were acquired at baseline (12 months), follow-up 1 (16 months) and follow-up 2 (18 months, termination scan), whereupon histological and biochemical analyses of Aβ were performed. We analyzed the PET data as VOI-based cortical standard-uptake-value ratios (SUVR), using cerebellum as reference region. Individual plaque load assessed by PET remained nearly constant in the TG-GSM group during 6 months of RO5506284 treatment, whereas it increased progressively in the TG-VEH group. Baseline SUVR in TG-GSM mice correlated with Δ%-SUVR, indicating individual response prediction. Insoluble Aβ42 was reduced by 56% in the TG-GSM versus the TG-VEH group relative to the individual baseline plaque load estimates. Furthermore, plaque size histograms showed differing distribution between groups of TG mice, with fewer small plaques in TG-GSM animals. Taken together, in the first Aβ-PET study monitoring prolonged treatment with a potent GSM in an AD mouse model, we found clear attenuation of de novo amyloidogenesis. Moreover, longitudinal PET allows non-invasive assessment of individual plaque-load kinetics, thereby accommodating inter-animal variations.
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Affiliation(s)
- M Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - A Jaworska
- DZNE—German Center for Neurodegenerative Diseases, Munich, Germany,Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - J Herms
- DZNE—German Center for Neurodegenerative Diseases, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - J Trambauer
- Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - C Rötzer
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - F-J Gildehaus
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - J Carlsen
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - P Cumming
- Department of Psychiatry, University of Oslo, Oslo, Norway
| | - J Bylund
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - T Luebbers
- Roche Pharma Research and Early Development, Small Molecule Research, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - P Bartenstein
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - H Steiner
- DZNE—German Center for Neurodegenerative Diseases, Munich, Germany,Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - C Haass
- DZNE—German Center for Neurodegenerative Diseases, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany,Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - K Baumann
- Roche Pharma Research and Early Development, Neuroscience Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - A Rominger
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany,Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Marchioninistr. 15, Munich 81377, Germany. E-mail:
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14
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Sundaram GS, Dhavale D, Prior JL, Sivapackiam J, Laforest R, Kotzbauer P, Sharma V. Synthesis, characterization, and preclinical validation of a PET radiopharmaceutical for interrogating Aβ (β-amyloid) plaques in Alzheimer's disease. EJNMMI Res 2015; 5:112. [PMID: 26061601 PMCID: PMC4478171 DOI: 10.1186/s13550-015-0112-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/22/2015] [Indexed: 02/03/2023] Open
Abstract
Background PET radiopharmaceuticals capable of imaging β-amyloid (Aβ) plaque burden in the brain could offer highly valuable diagnostic tools for clinical studies of Alzheimer’s disease. To further supplement existing armamentarium of FDA-approved agents as well as those under development, and to correlate multiphoton-imaging data reported earlier, herein, we describe preclinical validation of a PET tracer. Methods A novel PET radiopharmaceutical (18F-7B) was synthesized and characterized. To assess its affinity for Aβ, binding assays with Aβ1-42 fibrils, Alzheimer’s disease (AD) homogenates, and autoradiography studies and their IHC correlations were performed. For assessing its overall pharmacokinetic profiles in general and its ability to cross the blood-brain barrier (BBB) in particular, biodistribution studies in normal mice were performed. Finally, for evaluating potential for 18F-7B to serve as a targeted Aβ probe, the microPET/CT imaging was performed in age-matched amyloid precursor protein/presenilin-1 (APP/PS1) mice and wild-type (WT) counterparts. Results The radiotracer 18F-7B shows saturable binding to autopsy-confirmed AD homogenates (Kd = 17.7 nM) and Aβ1-42 fibrils (Kd = 61 nM). Preliminary autoradiography studies show binding of 18F-7B to cortical Aβ plaques in autopsy-confirmed AD tissue sections, inhibition of that binding by unlabeled counterpart 7A-indicating specificity, and a good correlation of tracer binding with Aβ immunostaining. The agent indicates high initial penetration into brains (7.23 ± 0.47%ID/g; 5 min) of normal mice, thus indicating a 5-min/120-min brain uptake clearance ratio of 4.7, a benchmark value (>4) consistent with the ability of agents to traverse the BBB to enable PET brain imaging. Additionally, 18F-7B demonstrates the presence of parental species in human serum. Preliminary microPET/CT imaging demonstrates significantly higher retention of 18F-7B in brains of transgenic mice compared with their WT counterparts, consistent with expected binding of the radiotracer to Aβ plaques, present in APP/PS1 mice, compared with their age-matched WT counterparts lacking those Aβ aggregates. Conclusions These data offer a platform scaffold conducive to further optimization for developing new PET tracers to study Aβ pathophysiology in vitro and in vivo.
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Affiliation(s)
- Guruswami Sm Sundaram
- ICCE Institute, Molecular Imaging Center, Box 8225, 510 S. Kingshighway Blvd., St. Louis, MO, 63110, USA,
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15
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Krohn M, Bracke A, Avchalumov Y, Schumacher T, Hofrichter J, Paarmann K, Fröhlich C, Lange C, Brüning T, von Bohlen und Halbach O, Pahnke J. Accumulation of murine amyloid-β mimics early Alzheimer’s disease. Brain 2015; 138:2370-82. [DOI: 10.1093/brain/awv137] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 03/27/2015] [Indexed: 11/13/2022] Open
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16
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Figini M, Zucca I, Aquino D, Pennacchio P, Nava S, Di Marzio A, Preti MG, Baselli G, Spreafico R, Frassoni C. In vivo DTI tractography of the rat brain: an atlas of the main tracts in Paxinos space with histological comparison. Magn Reson Imaging 2014; 33:296-303. [PMID: 25482578 DOI: 10.1016/j.mri.2014.11.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 12/30/2022]
Abstract
Diffusion tensor imaging (DTI) is a magnetic resonance modality that permits to characterize the orientation and integrity of white matter (WM). DTI-based tractography techniques, allowing the virtual reconstruction of WM tract pathways, have found wide application in preclinical neurological research. Recently, anatomically detailed rat brain atlases including DTI data were constructed from ex vivo DTI images, but tractographic atlases of normal rats in vivo are still lacking. We propose here a probabilistic tractographic atlas of the main WM tracts in the healthy rat brain based on in vivo DTI acquisition. Our study was carried out on 10 adult female Sprague-Dawley rats using a 7T preclinical scanner. The MRI protocol permitted a reliable reconstruction of the main rat brain bundles: corpus callosum, cingulum, external capsule, internal capsule, anterior commissure, optic tract. The reconstructed fibers were compared with histological data, proving the viability of in vivo DTI tractography in the rat brain with the proposed acquisition and processing protocol. All the data were registered to a rat brain template in the coordinate system of the commonly used atlas by Paxinos and Watson; then the individual tracts were binarized and averaged, obtaining a probabilistic atlas in Paxinos-Watson space of the main rat brain WM bundles. With respect to the recent high-resolution MRI atlases, the resulting tractographic atlas, available online, provides complementary information about the average anatomical position of the considered WM tracts and their variability between normal animals. Furthermore, reference values for the main DTI-derived parameters, mean diffusivity and fractional anisotropy, were provided. Both these results can be used as references in preclinical studies on pathological rat models involving potential alterations of WM.
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Affiliation(s)
- Matteo Figini
- Scientific Direction, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy; Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy
| | - Ileana Zucca
- Scientific Direction, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy.
| | - Domenico Aquino
- Neuroradiology Department, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
| | - Paolo Pennacchio
- Clinical Epileptology and Experimental Neurophysiology Unit, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
| | - Simone Nava
- Neuroradiology Department, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
| | - Alessandro Di Marzio
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy
| | - Maria Giulia Preti
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy; IRCCS S. Maria Nascente, Fondazione Don Carlo Gnocchi ONLUS, Milano, Italy
| | - Guseppe Baselli
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy
| | - Roberto Spreafico
- Clinical Epileptology and Experimental Neurophysiology Unit, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
| | - Carolina Frassoni
- Clinical Epileptology and Experimental Neurophysiology Unit, IRCCS Fondazione Istituto Neurologico "C. Besta", Milano, Italy
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17
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Hampel H, Lista S, Teipel SJ, Garaci F, Nisticò R, Blennow K, Zetterberg H, Bertram L, Duyckaerts C, Bakardjian H, Drzezga A, Colliot O, Epelbaum S, Broich K, Lehéricy S, Brice A, Khachaturian ZS, Aisen PS, Dubois B. Perspective on future role of biological markers in clinical therapy trials of Alzheimer's disease: a long-range point of view beyond 2020. Biochem Pharmacol 2013; 88:426-49. [PMID: 24275164 DOI: 10.1016/j.bcp.2013.11.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 11/13/2013] [Accepted: 11/13/2013] [Indexed: 10/26/2022]
Abstract
Recent advances in understanding the molecular mechanisms underlying various paths toward the pathogenesis of Alzheimer's disease (AD) has begun to provide new insight for interventions to modify disease progression. The evolving knowledge gained from multidisciplinary basic research has begun to identify new concepts for treatments and distinct classes of therapeutic targets; as well as putative disease-modifying compounds that are now being tested in clinical trials. There is a mounting consensus that such disease modifying compounds and/or interventions are more likely to be effectively administered as early as possible in the cascade of pathogenic processes preceding and underlying the clinical expression of AD. The budding sentiment is that "treatments" need to be applied before various molecular mechanisms converge into an irreversible pathway leading to morphological, metabolic and functional alterations that characterize the pathophysiology of AD. In light of this, biological indicators of pathophysiological mechanisms are desired to chart and detect AD throughout the asymptomatic early molecular stages into the prodromal and early dementia phase. A major conceptual development in the clinical AD research field was the recent proposal of new diagnostic criteria, which specifically incorporate the use of biomarkers as defining criteria for preclinical stages of AD. This paradigm shift in AD definition, conceptualization, operationalization, detection and diagnosis represents novel fundamental opportunities for the modification of interventional trial designs. This perspective summarizes not only present knowledge regarding biological markers but also unresolved questions on the status of surrogate indicators for detection of the disease in asymptomatic people and diagnosis of AD.
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Affiliation(s)
- Harald Hampel
- Université Pierre et Marie Curie, Département de Neurologie, Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Pavillon François Lhermitte, Hôpital de la Salpêtrière, Paris, France.
| | - Simone Lista
- Department of Psychiatry, Psychotherapy and Psychosomatics, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany.
| | - Stefan J Teipel
- Department of Psychosomatic Medicine, University of Rostock, Rostock, Germany; German Center for Neurodegenerative Diseases (DZNE) Rostock/Greifswald, Rostock, Germany
| | - Francesco Garaci
- Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology, and Radiotherapy, University of Rome "Tor Vergata", Rome, Italy; IRCCS San Raffaele Pisana, Rome and San Raffaele Cassino, Cassino, Italy
| | - Robert Nisticò
- Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy; IRCSS Santa Lucia Foundation, Rome, Italy
| | - Kaj Blennow
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - Henrik Zetterberg
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; University College London Institute of Neurology, Queen Square, London, UK
| | - Lars Bertram
- Department of Vertebrate Genomics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Charles Duyckaerts
- Laboratoire de Neuropathologie Raymond-Escourolle, Groupe Hospitalier Pitié-Salpêtrière, AP-HP, Paris, France
| | - Hovagim Bakardjian
- IM2A - Institute of Memory and Alzheimer's Disease, Paris, France; IHU-A-ICM - Paris Institute of Translational Neurosciences Pitié-Salpêtrière University Hospital, Paris, France
| | - Alexander Drzezga
- Department of Nuclear Medicine, University Hospital of Cologne, Cologne, Germany
| | - Olivier Colliot
- Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle Épinière, UMR-S975 Paris, France; Inserm, U975, Paris, France; CNRS, UMR 7225, Paris, France; ICM - Institut du Cerveau et de la Moelle Épinière, Paris, France; INRIA, Aramis Team, Centre de Recherche Paris-Rocquencourt, France
| | - Stéphane Epelbaum
- Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié Salpêtrière, Paris, France; Université Pierre et Marie Curie, Paris, France
| | - Karl Broich
- Federal Institute of Drugs and Medical Devices (BfArM), Bonn, Germany
| | - Stéphane Lehéricy
- IHU-A-ICM - Paris Institute of Translational Neurosciences Pitié-Salpêtrière University Hospital, Paris, France; Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle Épinière, UMR-S975 Paris, France; Inserm, U975, Paris, France; CNRS, UMR 7225, Paris, France; ICM - Institut du Cerveau et de la Moelle Épinière, Paris, France
| | - Alexis Brice
- Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle Épinière, UMR-S975 Paris, France; Inserm, U975, Paris, France; CNRS, UMR 7225, Paris, France; ICM - Institut du Cerveau et de la Moelle Épinière, Paris, France; AP-HP, Hôpital de la Salpêtrière, Département de Génétique et Cytogénétique, Paris, France
| | | | - Paul S Aisen
- Department of Neurosciences, University of California, San Diego, San Diego, CA, USA
| | - Bruno Dubois
- Institut de la Mémoire et de la Maladie d'Alzheimer (IM2A), Département de Neurologie, Hôpital de la Pitié Salpêtrière, Paris, France; Université Pierre et Marie Curie, Paris, France
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18
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Brendel M, Delker A, Rötzer C, Böning G, Carlsen J, Cyran C, Mille E, Gildehaus FJ, Cumming P, Baumann K, Steiner H, Haass C, Herms J, Bartenstein P, Rominger A. Impact of partial volume effect correction on cerebral β-amyloid imaging in APP-Swe mice using [(18)F]-florbetaben PET. Neuroimage 2013; 84:843-53. [PMID: 24055703 DOI: 10.1016/j.neuroimage.2013.09.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 09/03/2013] [Accepted: 09/10/2013] [Indexed: 11/17/2022] Open
Abstract
We previously investigated the progression of β-amyloid deposition in brain of mice over-expressing amyloid-precursor protein (APP-Swe), a model of Alzheimer's disease (AD), in a longitudinal PET study with the novel β-amyloid tracer [(18)F]-florbetaben. There were certain discrepancies between PET and autoradiographic findings, which seemed to arise from partial volume effects (PVE). Since this phenomenon can lead to bias, most especially in the quantitation of brain microPET studies of mice, we aimed in the present study to investigate the magnitude of PVE on [(18)F]-florbetaben quantitation in murine brain, and to establish and validate a useful correction method (PVEC). Phantom studies with solutions of known radioactivity concentration were performed to measure the full-width-at-half-maximum (FWHM) resolution of the Siemens Inveon DPET and to validate a volume-of-interest (VOI)-based PVEC algorithm. Several VOI-brain-masks were applied to perform in vivo PVEC on [(18)F]-florbetaben data from C57BL/6(N=6) mice, while uncorrected and PVE-corrected data were cross-validated with gamma counting and autoradiography. Next, PVEC was performed on longitudinal PET data set consisting of 43 PET scans in APP-Swe (13-20months) and age-matched wild-type (WT) mice using the previously defined masks. VOI-based cortex-to-cerebellum ratios (SUVR) were compared for uncorrected and PVE-corrected results. Brains from a subset of transgenic mice were ultimately examined by autoradiography ex vivo and histochemistry in vitro as gold standard assessments, and compared to VOI-based PET results. The phantom study indicated a FWHM of 1.72mm. Applying a VOI-brain-mask including extracerebral regions gave robust PVEC, with increased precision of the SUVR results. Cortical SUVR increased with age in APP-Swe mice compared to baseline measurements (16months: +5.5%, p<0.005; 20months: +15.5%, p<0.05) with uncorrected data, and to a substantially greater extent with PVEC (16months: +12.2% p<0.005; 20months: +36.4% p<0.05). WT animals showed no binding changes, irrespective of PVEC. Relative to autoradiographic results, the error [%] for uncorrected cortical SUVR was 18.9% for native PET data, and declined to 4.8% upon PVEC, in high correlation with histochemistry results. We calculate that PVEC increases by 10% statistical power for detecting altered [(18)F]-florbetaben uptake in aging APP-Swe mice in planned studies of disease modifying treatments on amyloidogenesis.
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Affiliation(s)
- Matthias Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-University, Munich, Germany
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19
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Rominger A, Brendel M, Burgold S, Keppler K, Baumann K, Xiong G, Mille E, Gildehaus FJ, Carlsen J, Schlichtiger J, Niedermoser S, Wängler B, Cumming P, Steiner H, Herms J, Haass C, Bartenstein P. Longitudinal assessment of cerebral β-amyloid deposition in mice overexpressing Swedish mutant β-amyloid precursor protein using 18F-florbetaben PET. J Nucl Med 2013; 54:1127-34. [PMID: 23729696 DOI: 10.2967/jnumed.112.114660] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED The progression of β-amyloid deposition in the brains of mice overexpressing Swedish mutant β-amyloid precursor protein (APP-Swe), a model of Alzheimer disease (AD), was investigated in a longitudinal PET study using the novel β-amyloid tracer (18)F-florbetaben. METHODS Groups of APP-Swe and age-matched wild-type (WT) mice (age range, 10-20 mo) were investigated. Dynamic emission recordings were acquired with a small-animal PET scanner during 90 min after the administration of (18)F-florbetaben (9 MBq, intravenously). After spatial normalization of individual PET recordings to common coordinates for mouse brain, binding potentials (BPND) and standardized uptake value ratios (SUVRs) were calculated relative to the cerebellum. Voxelwise analyses were performed using statistical parametric mapping (SPM). Histochemical analyses and ex vivo autoradiography were ultimately performed in a subset of animals as a gold standard assessment of β-amyloid plaque load. RESULTS SUVRs calculated from static recordings during the interval of 30-60 min after tracer injection correlated highly with estimates of BPND based on the entire dynamic emission recordings. (18)F-florbetaben binding did not significantly differ in APP-Swe mice and WT animals at 10 and 13 mo of age. At 16 mo of age, the APP-Swe mice had a significant 7.9% increase (P < 0.01) in cortical (18)F-florbetaben uptake above baseline and at 20 mo there was a 16.6% increase (P < 0.001), whereas WT mice did not show any temporal changes in tracer uptake during the interval of follow-up. Voxelwise SPM analyses revealed the first signs of increased cortical binding at 13 mo and confirmed progressive binding increases in both the frontal and the temporal cortices (P < 0.001 uncorrected) to 20 mo. The SUVR strongly correlated with percentage plaque load (R = 0.95, P < 0.001). CONCLUSION In the first longitudinal PET study in an AD mouse model using the novel β-amyloid tracer (18)F-florbetaben, the temporal and spatial progression of amyloidogenesis in the brain of APP-Swe mice were sensitively monitored. This method should afford the means for preclinical testing of novel therapeutic approaches to the treatment of AD.
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Affiliation(s)
- Axel Rominger
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany.
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20
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Lecanu L, Papadopoulos V. Modeling Alzheimer's disease with non-transgenic rat models. ALZHEIMERS RESEARCH & THERAPY 2013; 5:17. [PMID: 23634826 PMCID: PMC3706888 DOI: 10.1186/alzrt171] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD), for which there is no cure, is the most common form of dementia in the elderly. Despite tremendous efforts by the scientific community, the AD drug development pipeline remains extremely limited. Animal models of disease are a cornerstone of any drug development program and should be as relevant as possible to the disease, recapitulating the disease phenotype with high fidelity, to meaningfully contribute to the development of a successful therapeutic agent. Over the past two decades, transgenic models of AD based on the known genetic origins of familial AD have significantly contributed to our understanding of the molecular mechanisms involved in the onset and progression of the disease. These models were extensively used in AD drug development. The numerous reported failures of new treatments for AD in clinical trials indicate that the use of genetic models of AD may not represent the complete picture of AD in humans and that other types of animal models relevant to the sporadic form of the disease, which represents 95% of AD cases, should be developed. In this review, we will discuss the evolution of non-transgenic rat models of AD and how these models may open new avenues for drug development.
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Affiliation(s)
- Laurent Lecanu
- The Research Institute of the McGill University Health Centre, Royal Victoria Hospital, 687 Pine avenue West, room L2-05, Montreal H3A 1A1, QC, Canada ; Department of Medicine, McGill University, Royal Victoria Hospital, 687 Pine avenue West, room L2-05, Montreal H3A 1A1, QC, Canada
| | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Centre, Royal Victoria Hospital, 687 Pine avenue West, room L2-05, Montreal H3A 1A1, QC, Canada ; Department of Medicine, McGill University, Royal Victoria Hospital, 687 Pine avenue West, room L2-05, Montreal H3A 1A1, QC, Canada ; Departments of Biochemistry and Pharmacology and Therapeutics, McGill University, McIntyre Medical Sciences Bldg, 3655 Promenade Sir-William-Osler, room 1325, Montreal Quebec, Canada H3G 1Y6
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21
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Fröhlich C, Paarmann K, Steffen J, Stenzel J, Krohn M, Heinze HJ, Pahnke J. Genomic background-related activation of microglia and reduced β-amyloidosis in a mouse model of Alzheimer's disease. Eur J Microbiol Immunol (Bp) 2013; 3:21-27. [PMID: 23814667 DOI: 10.1556/eujmi.3.2013.1.3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Alzheimer's disease (AD) is by far the most common neurodegenerative disease. AD is histologically characterized not only by extracellular senile plaques and vascular deposits consisting of β-amyloid (Aβ) but also by accompanying neuroinflammatory processes involving the brain's microglia. The importance of the microglia is still in controversial discussion, which currently favors a protective function in disease progression. Recent findings by different research groups highlighted the importance of strain-specific and mitochondria-specific genomic variations in mouse models of cerebral β-amyloidosis. Here, we want to summarize our previously presented data and add new results that draw attention towards the consideration of strain-specific genomic alterations in the setting of APP transgenes. We present data from APP-transgenic mice in commonly used C57Bl/6J and FVB/N genomic backgrounds and show a direct influence on the kinetics of Aβ deposition and the activity of resident microglia. Plaque size, plaque deposition rate and the total amount of Aβ are highest in C57Bl/6J mice as compared to the FVB/N genomic background, which can be explained at least partially by a reduced microglia activity towards amyloid deposits in the C57BL/6J strain.
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Affiliation(s)
- Christina Fröhlich
- Neurodegeneration Research Lab (NRL), Department of Neurology, University of Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany
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22
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Manook A, Yousefi BH, Willuweit A, Platzer S, Reder S, Voss A, Huisman M, Settles M, Neff F, Velden J, Schoor M, von der Kammer H, Wester HJ, Schwaiger M, Henriksen G, Drzezga A. Small-animal PET imaging of amyloid-beta plaques with [11C]PiB and its multi-modal validation in an APP/PS1 mouse model of Alzheimer's disease. PLoS One 2012; 7:e31310. [PMID: 22427802 PMCID: PMC3302888 DOI: 10.1371/journal.pone.0031310] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 01/05/2012] [Indexed: 11/18/2022] Open
Abstract
In vivo imaging and quantification of amyloid-β plaque (Aβ) burden in small-animal models of Alzheimer's disease (AD) is a valuable tool for translational research such as developing specific imaging markers and monitoring new therapy approaches. Methodological constraints such as image resolution of positron emission tomography (PET) and lack of suitable AD models have limited the feasibility of PET in mice. In this study, we evaluated a feasible protocol for PET imaging of Aβ in mouse brain with [11C]PiB and specific activities commonly used in human studies. In vivo mouse brain MRI for anatomical reference was acquired with a clinical 1.5 T system. A recently characterized APP/PS1 mouse was employed to measure Aβ at different disease stages in homozygous and hemizygous animals. We performed multi-modal cross-validations for the PET results with ex vivo and in vitro methodologies, including regional brain biodistribution, multi-label digital autoradiography, protein quantification with ELISA, fluorescence microscopy, semi-automated histological quantification and radioligand binding assays. Specific [11C]PiB uptake in individual brain regions with Aβ deposition was demonstrated and validated in all animals of the study cohort including homozygous AD animals as young as nine months. Corresponding to the extent of Aβ pathology, old homozygous AD animals (21 months) showed the highest uptake followed by old hemizygous (23 months) and young homozygous mice (9 months). In all AD age groups the cerebellum was shown to be suitable as an intracerebral reference region. PET results were cross-validated and consistent with all applied ex vivo and in vitro methodologies. The results confirm that the experimental setup for non-invasive [11C]PiB imaging of Aβ in the APP/PS1 mice provides a feasible, reproducible and robust protocol for small-animal Aβ imaging. It allows longitudinal imaging studies with follow-up periods of approximately one and a half years and provides a foundation for translational Alzheimer neuroimaging in transgenic mice.
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Affiliation(s)
- André Manook
- Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
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23
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Hampel H, Prvulovic D, Teipel S, Jessen F, Luckhaus C, Frölich L, Riepe MW, Dodel R, Leyhe T, Bertram L, Hoffmann W, Faltraco F. The future of Alzheimer's disease: the next 10 years. Prog Neurobiol 2011; 95:718-28. [PMID: 22137045 DOI: 10.1016/j.pneurobio.2011.11.008] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Alzheimer's disease (AD) is a fast growing world-wide epidemic. AD is a genetically complex, slowly progressive, and irreversible neurodegenerative disease of the brain. During decades of asymptomatic progression multiple interactive systems, pathways and molecular mechanisms (e.g. protein processing, aberrant signaling, inflammation and immune system, lipid transport, endocytosis, apoptosis, oxidative damage and response to stress, tau pathology, neuron and synapse loss, energy metabolism), contribute to the development of the early clinical prodromal stage with episodic memory deficits and to further decline and loss of general cognitive functioning during the final syndromal dementia stage. The non-mendelian genetically complex "sporadic" AD type is the most common form of dementia affecting people usually over the age of 65. Despite considerable progress of AD research in recent years and evolving paradigm shifts in both pathophysiological concepts as well as in diagnostic criteria fundamental challenges have not yet been resolved. The strong age-related incidence, the recent failure and complete lack of disease-modifying or preventive therapy that may delay onset or substantially affect the pathophysiology of AD, result in an enormous burden posed both on individuals, their families and care givers, and the societies at large, and these call for urgent concerted worldwide measures. Based on the meeting of the German Task Force on Alzheimer's Disease (GTF-AD) in Paris on July 19th 2011, the present position paper provides an overview on the current state and future developments in epidemiology, pathophysiology, disease conceptualization, diagnostic criteria and their use in research and clinical practice, as well as preventive and symptomatic therapeutic approaches. Particular emphasis is placed on a discussion of the different approaches to diagnostics and therapy taken by preventive/public health medicine, methodologically advanced academic research propagating the use of sophisticated biomarkers, and everyday clinical practice focusing on patient-centered care. During the next 10 years, major advances both in early detection as well as in therapy and comprehensive AD care seem mandatory. These still unmet needs call for ever more concerted and focused efforts in research across the world to combat the erupting and as yet uncontrolled epidemic of AD.
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Affiliation(s)
- Harald Hampel
- Department of Psychiatry, Psychosomatic Medicine & Psychotherapy, Goethe University, Frankfurt, Germany.
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